The present invention is directed to a coupling device for coupling two optical waveguides having different cross sections to one another and in particular for coupling a layer conductor to a strip conductor.
In order to produce a laser transmitter for optical communications technique, which transmitter consists of a waveguide laser, which, for example, is formed with a stoichiometric neodymium compound, and a subsequent waveguide modulator, which consists of an electro-optical material, for example of lithium niobate, it is necessary to couple the waveguides of the two components with a low loss. The considerable problems, which this type of coupling arrangement must be resolved, are the adjustment of the cross-sectional area, for example the adjustment of a cross-sectional area of 10.times.30 .mu.m.sup.2 in the laser to a cross section of approximately 4.times.3 .mu.m in a waveguide modulator and the phase adjustment, for example the adjustment of a refractive index of approximately 2.2 in the waveguide modulator.